I have 2 male purple moscows guppies and 2 bottom feeders in my 20 gal.
I also have 4 female purple moscow guppies and two bottom feeders in another 20 gal tank.
Im getting 2 more trios of green delta guppies in a couple weeks. They will be around the same age as my purples. Would it be best to keep the greens seperate from the purples, or does it not matter. Sexes will never be together unless for mating purposes. Thanks

Keep virgin females together and males together? Will probably work unless one strain is larger, faster, or meaner than the other. Also a risk of infection (trading germs like kids @ school). Do QT new fish. I keep fish separate for ease of catching. If females are non-virgin you may have "mystery fry" appear in the tank.